Frank, the xml namespace appears to be correct but I don't know if it applies to the grid. Try taking the "Custom:" off the grid to see if the grid resolves. I can't remember in 2008 (short memory I guess) if the grid was included in wpf yet.

My grid definition does not come from "custom" but I am in VS2010
Tim

>Hi,
>
>for fun this morning I thought I'd play around a bit with the MM.NET WPF Jump Start. In creating the Customer Orders Window I get two errors:
>
>The tag 'DataGrid' does not exist in XML namespace 'http://schemas.microsoft.com/wpf/2008/toolkit'.
>
>The type 'Custom:DataGrid' was not found. Verify that you are not missing an assembly reference and that all referenced assemblies have been built.
>
>I've rebuilt everything but that didn't help
>
>I'm assuming I need to add a reference to the project, but which one?
>
>UPDATE:
>
>I see the reference in the XAML for custom is this:
>
>xmlns:Custom="http://schemas.microsoft.com/wpf/2008/toolkit"
>
>So I guess this value is wrong, what should it be?